Books have been set forth on this issue, and the disquiet and ruckus about where the "hot" slot games are placed in the casino are still ongoing – over sixty years after the slot machines were 1st placed in gambling dens.
The standard rule is that the very best slot machines were put just inside the main doorway of the casino; so that persons passing by would see jackpot winners and be smitten to come into the casino … play. Our philosophy is that this is definitely no longer the case.
Nearly all of the big name casinos presently are monstrous complexes … you can no longer see inside from the sidewalk, so there is no longer a reason to have the ‘loose’ slots close-by any of the doors.
An additional classic rule is that loose slots are located on the major aisles in the casinos, again so that more folks could see winning jackpots and be encouraged to play. Nonetheless, we find that this also is no longer a universal rule.
What casinos found over the years is that people walking down the busy aisles were frequently on the way to somewhere else. If they played slot machine games at all, they would simply put in their loose change because they happened to be walking by. Win or lose, they would very often not stop to keep playing. And the very last thing a casino wants is for someone to win a jackpot by playing only a few coins and then not stay to put it all back in!
These days, casinos are constantly changing their perspective about where to place the loose slot machines.